2005 NISSAN X-TRAIL Air conditioner

ATC-28
AIR CONDITIONER CONTROL

TRANSMISSION DATA AND TRANSMISSION ORDER
Auto amp. data is transmitted consecutively to each of the door motors following the form shown in figure
below.
Start:
Initial compulsory signal sent to each of the door motors.
Address:
Data sent from the auto amp. is selected according to data-based decisions made by the air mix door motor,
mode door motor and intake door motor.
If the addresses are identical, the opening angle data and error check signals are received by the door motor
LCUs. The LCUs then make the appropriate error decision. If the opening angle data is usual, door control
begins.
If an error exists, the received data is rejected and corrected data received. Finally, door control is based upon
the corrected opening angle data.
Opening Angle:
Data that shows the indicated door opening angle of each door motor.
Error Check:
Procedure by which sent and received data is checked for errors. Error data is then compiled. The error check
prevents corrupted data from being used by the air mix door motor, mode door motor and intake door motor.
Error data can be related to the following symptoms.

Malfunction electrical frequency

Poor electrical connections

Signal leakage from transmission lines

Signal level fluctuation
RHA351H

AIR CONDITIONER CONTROL
ATC-29
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Stop Signal:
At the end of each transmission, a stop operation, in-operation, or internal malfunction message is delivered to
the auto amp. This completes one data transmission and control cycle.
AIR MIX DOOR CONTROL (AUTOMATIC TEMPERATURE CONTROL)
The air mix door is automatically controlled so that in-vehicle temperature is maintained at a predetermined
value by the temperature setting, ambient temperature, in-vehicle temperature and amount of sunload.
FAN SPEED CONTROL
Blower speed is automatically controlled by the temperature setting, ambient temperature, in-vehicle tempera-
ture, intake temperature, amount of sunload and air mix door position.
With FAN control dial set to AUTO, the blower motor starts to gradually increase air flow volume.
When engine coolant temperature is low, the blower motor operation is delayed to prevent cool air from flow-
ing.
INTAKE DOOR CONTROL
The intake doors are automatically controlled by the temperature setting, ambient temperature, in-vehicle tem-
perature, intake temperature, amount of sunload and ON-OFF operation of the compressor.
OUTLET DOOR CONTROL
The outlet door is automatically controlled by the temperature setting, ambient temperature, in-vehicle temper-
ature, intake temperature and amount of sunload.
MAGNET CLUTCH CONTROL
The ECM controls compressor operation using input signals from the throttle position sensor, refrigerant pres-
sure sensor (or dual-pressure switch) and auto amp.
SELF-DIAGNOSTIC SYSTEM
The self-diagnostic system is built into the auto amp. to quickly locate the cause of symptoms.
RHA352H

ATC-30
AIR CONDITIONER CONTROL

Description of Control SystemEJS000TK
The control system consists of input sensors, switches, the auto amp. (microcomputer) and outputs.
The relationship of these components is shown in the diagram below:
RJIA3093E

AIR CONDITIONER CONTROL
ATC-31
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Control OperationEJS004G9
MODE CONTROL DIAL
Controls the air discharge outlets.
Positions the air outlet doors to the defrost position. Also positions the intake doors to the outside air position.
When shifting mode control dial to DEF under the following conditions, compressor is turned ON. (A/C LED
ON)

FAN: O N

A/C: OFF
TEMPERATURE CONTROL DIAL (POTENTIO TEMPERATURE CONTROL)
Increase or decrease the set temperature.
FAN CONTROL DIAL
Automatically or Manually control the blower speed. Twenty-five speeds are available for manual control.
Shifting fan control dial to AUTO, compressor is turned ON automatically.
REAR WINDOW DEFOGGER SWITCH
When illumination is ON, rear window is defogged.
INTAKE SWITCH

When intake switch is ON, REC indicator turns ON, and air inlet is fixed to REC.

When press intake switch again, FRE indicator turns ON, and air inlet is fixed to FRE.

When intake switch is pressed for approximately 1.5 seconds or longer, REC and FRE indicators blink
twice. Then, automatic control mode is entered. Inlet status is displayed even during automatic control.

When DEF position or FRE indicator is turned ON, or when compressor is turned from ON to OFF, REC
switch is automatically turned OFF (fixed to FRE mode).
REC mode can be re-entered by pressing intake switch again. (Except DEF position)
A/C SWITCH
The compressor is ON or OFF.
(Pressing the A/C switch when the fan control dial is ON will turn off the A/C switch and compressor.)
SJIA0386E

ATC-32
AIR CONDITIONER CONTROL

Discharge Air FlowEJS000TM
SJIA0441E

AIR CONDITIONER CONTROL
ATC-33
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System DescriptionEJS000TN
SWITCHES AND THEIR CONTROL FUNCTION
SJIA0448E
RJIA2822E

ATC-60
TROUBLE DIAGNOSIS

5. STEP-2: SENSOR CIRCUITS ARE CHECKED FOR OPEN OR SHORT CIRCUIT
1. Turn fan control dial to AUTO position.
2. Turn mode control dial to AUTO position.
CAUTION:
When switched to STEP-2, LED of REC position blinks for
approximately 25 seconds.
3. Check A/C switch LED is illuminate.
OK or NG
OK >> GO TO 6.
NG >> GO TO 9.
6. STEP-3: MODE DOOR AND INTAKE DOOR POSITIONS ARE CHECKED
1. Turn fan control dial to 1st–12th speed.
2. Check A/C switch LED is illuminate.
CAUTION:
When switched to STEP-3, LED of REC position blinks for
approximately 50 seconds.
OK or NG
OK >> GO TO 7.
NG >> GO TO 10.
7. STEP-4: OPERATION OF EACH ACTUATOR IS CHECKED
1. Turn fan control dial to 13th–25th speed.
2. Change operation status of air conditioner by changing mode control dial position.
>> GO TO 8.
SJIA0391E
SJIA0392E

TROUBLE DIAGNOSIS
ATC-67
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Power Supply and Ground Circuit for Auto Amp.EJS004GV
SYMPTOM: A/C system does not come on.
INSPECTION FLOW
COMPONENT DESCRIPTION
Auto Amp. (Automatic Amplifier)
The auto amp. has a built-in microcomputer which processes infor-
mation sent from various sensors needed for air conditioner opera-
tion. The air mix door motor, mode door motor, intake door motor,
blower motor and compressor are then controlled.
The auto amp. is unitized with control mechanisms. Signals from
various switches and Potentio Temperature Control (PTC) are
directly entered into auto amp.
Self-diagnostic functions are also built into auto amp. to provide
quick check of malfunctions in the auto air conditioner system.
*1AT C - 6 5 , "Operational Check".*2ATC-68, "DIAGNOSTIC PROCE-
DURE FOR A/C SYSTEM".
RJIA2826E
RJIA2824E